GUANTANAMO BAY U.S. NAVAL BASE, Cuba, April 27 (Reuters) - An al Qaeda suspect told a U.S. military tribunal on Thursday that he was proud of fighting against the United States and willing to spend the rest of his life in prison as a "matter of honor."

"I came here to tell you I did what I did and I'm willing to pay the price," said Ghassan Abdullah al Sharbi, 31, a U.S.-educated Saudi who allegedly met al Qaeda leader Osama bin Laden at a training camp in Afghanistan months before the Sept. 11 attacks.

"Even if I spend hundreds of years in jail, that would be a matter of honor to me," he said.

Sporting long dark hair and a flowing beard, Sharbi appeared at a pretrial tribunal hearing near the U.S. prison camp at Guantanamo Bay, Cuba, as one of 10 detainees who face life imprisonment if convicted of war crimes. About 490 detainees are held at Guantanamo.

The tribunal also held hearings this week for two alleged co-conspirators -- Algerian Sufyian Barhoumi and Saudi Jabran Said bin al Qahtani. The U.S. military says the three were part of an al Qaeda bomb-making cell.

"I fought the United States," Sharbi told the presiding officer, Navy Capt. Daniel O'Toole. "I'm going to make it short and easy for you guys: I'm proud of what I did."

Sharbi rejected the notion that he was "guilty" of wrongdoing and politely said he wanted to represent himself. He rejected his appointed military lawyer, Navy Lt. William Kuebler, and said he wanted neither a military replacement nor a civilian defender.

"It's the same circus, different clown," said Sharbi, a fluent English speaker who earned an electrical engineering degree at Embry-Riddle Aeronautical University in Arizona before leaving the United States for Afghanistan in 2000.

O'Toole tried to order Kuebler to remain Sharbi's lawyer. But Kuebler told the presiding officer that legal authorities in California had advised him it was unethical to represent an unwilling client.

O'Toole then cut short the proceedings and set a May 17 hearing to consider the ethics issue.

Qahtani's defense lawyer, Army Lt. Col. Bryan Broyles, whose client is boycotting the tribunals, said detainee remarks like Sharbi's were understandable under a tribunal system that rights advocates say has been stacked to deliver convictions.

"They're not making a mockery of the system, they're saying the system is a mockery of justice," Broyles told reporters.

The legality of the tribunals, which President George W. Bush created to try foreigners suspected of terrorism after the Sept. 11 attacks, has been challenged before the U.S. Supreme Court. A high court ruling is expected in June.

The chief prosecutor, Air Force Col. Moe Davis, said Sharbi, Qahtani, Barhoumi and others who face only conspiracy charges would have to begin the tribunal process anew if the Supreme Court ruled that conspiracy did not constitute a war crime.

Military documents allege that Sharbi was introduced to bin Laden in July 2001 at al Qaeda's al Farouq training camp in Afghanistan, where he underwent basic training, stood guard and kept watch for U.S. air strikes after the Sept. 11 attacks.

He was moved by former al Qaeda operations director Abu Zubaydah to a safe house in Faisalabad, Pakistan, for training in the construction of electronic detonators later used in car bomb attacks on U.S. forces in Afghanistan, the military says.

Sharbi, Barhoumi, Qahtani and Zubaydah were captured there together in March 2002, military documents say.